ÉTUDE HYDROCHIMIQUE ET MICROBIOLOGIQUE DES NAPPES D’ALTÉRITES SOUS CLIMAT TROPICAL HUMIDE : CAS DU DÉPARTEMENT D’ABENGOUROU (SUD-EST DE LA CÔTE D’IVOIRE)

Abstract

The physico-chemical and microbiological properties of regolith aquifers in the department of Abengourou were evaluated for the use of drinking water. The 32 traditional water wells and three streams were sampled in December (dry season) 2009 and analyzed. The results submitted to statistical treatment showed that most downgrading physicochemical parameters pH, Iron, Aluminium and nitrates which respectively 90%, 30%, 70% and 28% of water points are higher levels to WHO standards. Facies in 50% of cases are most chlorinated or nitrated sodi-potassic. A significant correlation was observed between the electrical conductivity and Na+, K+, Mg2+, NO3 -, Cl-. Mineralization of water is controlled by phenomena such as atmospheric deposition, and anthropogenic acid hydrolysis rocks. Microbiological analysis revealed the presence of Escherichia coli (10 to 150 cfu/100 ml) in 28% of the wells. Water Resources of department are subject to significant anthropogenic pressure. The consumption of these waters for a large number of wells without any treatment is to be avoided because it could be a source of health risks for populations.